Pawn, such Pawn need not necessarily be exchanged for a Queen. You may claim a Rook, or a Bishop, or a Knight. And this privilege is allowed even though all the pieces remain on the board. It follows, therefore, that you may have two or more Queens, and three or more Rooks, Bishops, or Knights. Remember that the promotion of the Pawn is the immediate consequence of its attaining the eighth square. A move cannot be played until this promotion is made.

In the following problem, if Black have the move, he can check-mate you immediately, or, "on the move," as it is called. Endeavour to find out how he can do this. But White having to move, you can force the mate in three

moves. You first sacrifice your Bishop in order to get the adverse King into such a position that the mate can be effected

FORKING WITH QUEEN OR KNIGHT—THE EXCHANGE. 63

in the shortest way. Therefore, by checking with the B. at Q. Kt. 6th, the King has the choice of moving to his Q. R. sq. or of capturing your B. If he move to his Q. R. sq., your advanced Pawn moves to Queen, becomes a Queen, and gives check-mate. His best move (when acting on the deensive, that which will prolong the game is generally called he best move), is to take the B., which he does accordingly. Now, although a Queen is the most valuable piece to get in exchange for a Pawn, yet it is not always the most advan tageous. In the present case, if you claim a Queen for your Pawn, she will be of no use to you, because she does not give check, and your adversary can mate you ií you cease to check him. To check him, by playing your Rook to Q. B. sixth is of no use, because the Rook can be captured by K. or by Q. You, therefore, queen your Pawn, and instead of claiming a Queen, you take a Knight, which thus gives check. He cannot capture the Kt., and has only one vacant square to which his King can move, because you will observe that your newly created Kt. not only checks the K. at his Q. Kt. 3d, but also commands his Q. R. 2d. His King must, therefore, move to Q. R. 4th sq., when you can mate him immediately by a move which you will readily discover.

The following diagram illustrates a power which belongs to the Pawn and the Kt., of attacking two men at once: this is called forking them. For example, by playing your Kt. to K. 7th, you fork your adversary's King and Rook. He must move his King out of check, and you capture the Rook: should he retake with his B., you are then said to win the exchange, a term which is used when you gain a Rook in exchange for a Knight or Bishop.

The power of forking also applies to the Pawn. In this diagram, by playing Q. B. P. two sq., you fork his Kt. and B.: he cannot save both, and must either lose his Kt. by moving away his B., or, by taking the P. lose his B. for a P.

LESSON IX.

BEFORE proceeding to instruct you how to win the game when you have a King and Pawn against your adversary's King, or if you have the King only, how to draw; it will be

necessary to teach you what is meant by having or gaining the opposition, as it is commonly termed many a game is lost, which would otherwise be drawn, from not understanding how to gain the opposition with the King, and yet it is not by any means very difficult.

As one King cannot attack the other, it follows, of course, that there must always be at least one square between the two Kings; hence, the following situations will show that he K. has considerable power in preventing the advance of the adverse King, and in cutting him off from the occupation of many squares; for example:

In this position it is clear that your King prevents the Black from playing his K. to the second rank, nor can he

ever play to that rank if he have to move first, in which case you are said to have the opposition; but if you were to move first, he would have the opposition, and would be able to play to the second rank; for instance:

Here he is able to quit the side of the board, because you were obliged to give up the opposition, having the first move. If it were an object to the Black to prevent your King from advancing, he would easily do it if you begin, but not so if he begin; for example:

1. K. to K. B. sq. 1. K. to Q. 7h sq. &c.